A very rare unusual site of ventilator breathing circuit leakage: Beware!!

Sir,

The leakage in the anesthesia circuit may lead to life threatening complications. Likewise, the leakage in the ventilator circuit or machine itself may become life-threatening complications in critically ill patient who are on ventilator support. There are various reports of leakage in anesthesia circuit or machine related problems.[1] As per my knowledge, the leakage in breathing system among critical care unit patients have not been reported. I reported an incident of very rare unusual site of air leak from the breathing circuit and was challenging to identify.

In our critical care unit, monitoring of end-tidal carbon dioxide (EtCO2) is mandatory during mechanical ventilation due to various reasons. The monitoring of EtCO2 helps to diagnose various pathological conditions and also it is an indirect noninvasive measure of arterial CO2. It can also be used for monitoring of effective chest compression during cardiopulmonary resuscitation.[2] Use of such monitoring system reduces the frequency of invasive investigations such as arterial blood gas analysis. Practicing cost-effective treatment is a very challenging task in developing and underdeveloped countries.[3] Since monitoring EtCO2 is an economical method, it is practiced in our set up routinely.

A 75-year-old female with the cerebrovascular accident was admitted in our rural tertiary care set up and was on ventilator support as her Glasgow Coma Scale was 3. As per our institutional protocol, the ventilator precheck will be conducted before connecting the breathing circuit to the patient. Savina ventilator 300 (Drager make) passed all the electronic self-check and showed a leak <25 ml.

After connecting to the breathing, circuit ventilator started giving alarm and data showed 75% leak of minute ventilation [Figure 1a and b]. The breathing circuits, bacterial filter, and even the ventilator was changed to cross verify the problem. The problem persisted even with these measures. The adequate pressure and inflation of tracheostomy cuff were reconfirmed. After confirming that no leaky points in all the parts of breathing circuit a high index of suspicion was made on EtCO2 module. The patient was ventilated without the EtCO2 module. The ventilator alarm of leakage was disappeared thereafter. A close examination of the module revealed damaged part of cuvette, wherein a diaphragm part was missing. Since it is transparent, the damage could not be easily identified [Figure 1c and d]. A new cuvette was inserted, and the ventilator tubing was reconnected to the patient. The alarm disappeared, and the amount of leak was nil [Figure 1e and f]. In this case, the ventilator safety features and graphics helped to consider the problem seriously. A high index of suspicion and knowledge of such rare complications helps in careful management of critically ill patient and also prevents life – threatening complications.

Figure 1

(a) Leakage alarm (b) percentage of leakage (c) an intravenous cannula blocker was placed to demonstrate damaged diaphragm (d) an intravenous cannula blocker was placed to demonstrate intact transparent diaphragm (e) disappearance of alarm and normal ventilator graphics (f) 0% leakage after rectification of problem

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.